<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>1-1</title>
    <style>
        #outer{
            width:500px;
            margin:0 auto;
            padding:0;
            text-align:center;
        }
        #div1{
            width:100px;
            height:100px;
            background:black;
            margin:10px auto;
            display:block;
        }
    </style>
    <script>
        var changeStyle = function (elem, attr, value){
            elem.style[attr] = value
        };
        window.onload = function (){
            var oBtn = document.getElementsByTagName("input");
            var oDiv = document.getElementById("div1");	
            var oAtt = ["width","height","background","display","display"];
            var oVal = ["200px","200px","yellow","none","block"];

            for (var i = 0; i < oBtn.length; i++){
                oBtn[i].index = i;
                oBtn[i].onclick = function (){
                    changeStyle(oDiv, oAtt[this.index], oVal[this.index]);
                    this.index == oBtn.length - 1 && (oDiv.style.cssText = "");
                }
            }
        };
    </script>
</head>
<body>
<div id="outer">
    <input type="button" value="变宽" />
    <input type="button" value="变高" />
    <input type="button" value="变色" />
    <input type="button" value="隐藏" />
    <input type="button" value="重置" />
    <div id="div1"></div>
</div>
</body>
</html>
